ec2: add support for rendering public IP addresses in network config

[ubuntu-server-builder]

This bug was originally filed in Launchpad as LP: #1867197

Launchpad details

affected_projects = []
assignee = None
assignee_name = None
date_closed = None
date_created = 2020-03-12T19:14:52.711395+00:00
date_fix_committed = None
date_fix_released = None
id = 1867197
importance = medium
is_complete = False
lp_url = https://bugs.launchpad.net/cloud-init/+bug/1867197
milestone = None
owner = chad.smith
owner_name = Chad Smith
private = False
status = triaged
submitter = chad.smith
submitter_name = Chad Smith
tags = []
duplicates = []

Launchpad user Chad Smith(chad.smith) wrote on 2020-03-12T19:14:52.711395+00:00

cloud-init 20.1 currently renders only local ip address information in the network configuration emitted for attached NICs.

Ec2 instances can be launched and configured with multiple public IP addresses

https://aws.amazon.com/blogs/aws/multiple-ip-addresses-for-ec2-instances-in-a-virtual-private-cloud/

Ec2 IMDS network data exposes public IPv4 addresses in the following metadata keys:

• network.interfaces.macs.<MAC_ADDR>.public-ipv4s = "18.218.219.181"
• and an association of public ip to the private IPs allocated via the key
  "ipv4-associations": {
   "18.218.219.181": "172.31.44.13"
   },

Cloud-init should render known public ipv4 address configuration on the node to avoid network round trips for local services that may connect with the VMs known public IP